drivers/net/wireless/ath/carl9170/fw.c - arm/linux - Git at Google

 /*
  * Atheros CARL9170 driver
  *
  * firmware parser
  *
  * Copyright 2009, 2010, Christian Lamparter <chunkeey@googlemail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; see the file COPYING.  If not, see
  * http://www.gnu.org/licenses/.
  */

 #include <linux/kernel.h>
 #include <linux/firmware.h>
 #include <linux/crc32.h>
 #include <linux/module.h>
 #include "carl9170.h"
 #include "fwcmd.h"
 #include "version.h"

 static const u8 otus_magic[4] = { OTUS_MAGIC };

 static const void *carl9170_fw_find_desc(struct ar9170 *ar, const u8 descid[4],
 	const unsigned int len, const u8 compatible_revision)
 {
 	const struct carl9170fw_desc_head *iter;

 	carl9170fw_for_each_hdr(iter, ar->fw.desc) {
 		if (carl9170fw_desc_cmp(iter, descid, len,
 					compatible_revision))
 			return (void *)iter;
 	}

 	/* needed to find the LAST desc */
 	if (carl9170fw_desc_cmp(iter, descid, len,
 				compatible_revision))
 		return (void *)iter;

 	return NULL;
 }

 static int carl9170_fw_verify_descs(struct ar9170 *ar,
 	const struct carl9170fw_desc_head *head, unsigned int max_len)
 {
 	const struct carl9170fw_desc_head *pos;
 	unsigned long pos_addr, end_addr;
 	unsigned int pos_length;

 	if (max_len < sizeof(*pos))
 		return -ENODATA;

 	max_len = min_t(unsigned int, CARL9170FW_DESC_MAX_LENGTH, max_len);

 	pos = head;
 	pos_addr = (unsigned long) pos;
 	end_addr = pos_addr + max_len;

 	while (pos_addr < end_addr) {
 		if (pos_addr + sizeof(*head) > end_addr)
 			return -E2BIG;

 		pos_length = le16_to_cpu(pos->length);

 		if (pos_length < sizeof(*head))
 			return -EBADMSG;

 		if (pos_length > max_len)
 			return -EOVERFLOW;

 		if (pos_addr + pos_length > end_addr)
 			return -EMSGSIZE;

 		if (carl9170fw_desc_cmp(pos, LAST_MAGIC,
 					CARL9170FW_LAST_DESC_SIZE,
 					CARL9170FW_LAST_DESC_CUR_VER))
 			return 0;

 		pos_addr += pos_length;
 		pos = (void *)pos_addr;
 		max_len -= pos_length;
 	}
 	return -EINVAL;
 }

 static void carl9170_fw_info(struct ar9170 *ar)
 {
 	const struct carl9170fw_motd_desc *motd_desc;
 	unsigned int str_ver_len;
 	u32 fw_date;

 	dev_info(&ar->udev->dev, "driver   API: %s 2%03d-%02d-%02d [%d-%d]\n",
 		CARL9170FW_VERSION_GIT, CARL9170FW_VERSION_YEAR,
 		CARL9170FW_VERSION_MONTH, CARL9170FW_VERSION_DAY,
 		CARL9170FW_API_MIN_VER, CARL9170FW_API_MAX_VER);

 	motd_desc = carl9170_fw_find_desc(ar, MOTD_MAGIC,
 		sizeof(*motd_desc), CARL9170FW_MOTD_DESC_CUR_VER);

 	if (motd_desc) {
 		str_ver_len = strnlen(motd_desc->release,
 			CARL9170FW_MOTD_RELEASE_LEN);

 		fw_date = le32_to_cpu(motd_desc->fw_year_month_day);

 		dev_info(&ar->udev->dev, "firmware API: %.*s 2%03d-%02d-%02d\n",
 			 str_ver_len, motd_desc->release,
 			 CARL9170FW_GET_YEAR(fw_date),
 			 CARL9170FW_GET_MONTH(fw_date),
 			 CARL9170FW_GET_DAY(fw_date));

 		strlcpy(ar->hw->wiphy->fw_version, motd_desc->release,
 			sizeof(ar->hw->wiphy->fw_version));
 	}
 }

 static bool valid_dma_addr(const u32 address)
 {
 	if (address >= AR9170_SRAM_OFFSET &&
 	    address < (AR9170_SRAM_OFFSET + AR9170_SRAM_SIZE))
 		return true;

 	return false;
 }

 static bool valid_cpu_addr(const u32 address)
 {
 	if (valid_dma_addr(address) || (address >= AR9170_PRAM_OFFSET &&
 	    address < (AR9170_PRAM_OFFSET + AR9170_PRAM_SIZE)))
 		return true;

 	return false;
 }

 static int carl9170_fw_checksum(struct ar9170 *ar, const __u8 *data,
 				size_t len)
 {
 	const struct carl9170fw_otus_desc *otus_desc;
 	const struct carl9170fw_last_desc *last_desc;
 	const struct carl9170fw_chk_desc *chk_desc;
 	unsigned long fin, diff;
 	unsigned int dsc_len;
 	u32 crc32;

 	last_desc = carl9170_fw_find_desc(ar, LAST_MAGIC,
 		sizeof(*last_desc), CARL9170FW_LAST_DESC_CUR_VER);
 	if (!last_desc)
 		return -EINVAL;

 	otus_desc = carl9170_fw_find_desc(ar, OTUS_MAGIC,
 		sizeof(*otus_desc), CARL9170FW_OTUS_DESC_CUR_VER);
 	if (!otus_desc) {
 		dev_err(&ar->udev->dev, "failed to find compatible firmware "
 			"descriptor.\n");
 		return -ENODATA;
 	}

 	chk_desc = carl9170_fw_find_desc(ar, CHK_MAGIC,
 		sizeof(*chk_desc), CARL9170FW_CHK_DESC_CUR_VER);

 	if (!chk_desc) {
 		dev_warn(&ar->udev->dev, "Unprotected firmware image.\n");
 		return 0;
 	}

 	dsc_len = min_t(unsigned int, len,
 			(unsigned long)chk_desc - (unsigned long)otus_desc);

 	fin = (unsigned long) last_desc + sizeof(*last_desc);
 	diff = fin - (unsigned long) otus_desc;

 	if (diff < len)
 		len -= diff;

 	if (len < 256)
 		return -EIO;

 	crc32 = crc32_le(~0, data, len);
 	if (cpu_to_le32(crc32) != chk_desc->fw_crc32) {
 		dev_err(&ar->udev->dev, "fw checksum test failed.\n");
 		return -ENOEXEC;
 	}

 	crc32 = crc32_le(crc32, (void *)otus_desc, dsc_len);
 	if (cpu_to_le32(crc32) != chk_desc->hdr_crc32) {
 		dev_err(&ar->udev->dev, "descriptor check failed.\n");
 		return -EINVAL;
 	}
 	return 0;
 }

 static int carl9170_fw_tx_sequence(struct ar9170 *ar)
 {
 	const struct carl9170fw_txsq_desc *txsq_desc;

 	txsq_desc = carl9170_fw_find_desc(ar, TXSQ_MAGIC, sizeof(*txsq_desc),
 					  CARL9170FW_TXSQ_DESC_CUR_VER);
 	if (txsq_desc) {
 		ar->fw.tx_seq_table = le32_to_cpu(txsq_desc->seq_table_addr);
 		if (!valid_cpu_addr(ar->fw.tx_seq_table))
 			return -EINVAL;
 	} else {
 		ar->fw.tx_seq_table = 0;
 	}

 	return 0;
 }

 static void carl9170_fw_set_if_combinations(struct ar9170 *ar,
 					    u16 if_comb_types)
 {
 	if (ar->fw.vif_num < 2)
 		return;

 	ar->if_comb_limits[0].max = ar->fw.vif_num;
 	ar->if_comb_limits[0].types = if_comb_types;

 	ar->if_combs[0].num_different_channels = 1;
 	ar->if_combs[0].max_interfaces = ar->fw.vif_num;
 	ar->if_combs[0].limits = ar->if_comb_limits;
 	ar->if_combs[0].n_limits = ARRAY_SIZE(ar->if_comb_limits);

 	ar->hw->wiphy->iface_combinations = ar->if_combs;
 	ar->hw->wiphy->n_iface_combinations = ARRAY_SIZE(ar->if_combs);
 }

 static int carl9170_fw(struct ar9170 *ar, const __u8 *data, size_t len)
 {
 	const struct carl9170fw_otus_desc *otus_desc;
 	int err;
 	u16 if_comb_types;

 	err = carl9170_fw_checksum(ar, data, len);
 	if (err)
 		return err;

 	otus_desc = carl9170_fw_find_desc(ar, OTUS_MAGIC,
 		sizeof(*otus_desc), CARL9170FW_OTUS_DESC_CUR_VER);
 	if (!otus_desc) {
 		return -ENODATA;
 	}

 #define SUPP(feat)						\
 	(carl9170fw_supports(otus_desc->feature_set, feat))

 	if (!SUPP(CARL9170FW_DUMMY_FEATURE)) {
 		dev_err(&ar->udev->dev, "invalid firmware descriptor "
 			"format detected.\n");
 		return -EINVAL;
 	}

 	ar->fw.api_version = otus_desc->api_ver;

 	if (ar->fw.api_version < CARL9170FW_API_MIN_VER ||
 	    ar->fw.api_version > CARL9170FW_API_MAX_VER) {
 		dev_err(&ar->udev->dev, "unsupported firmware api version.\n");
 		return -EINVAL;
 	}

 	if (!SUPP(CARL9170FW_COMMAND_PHY) || SUPP(CARL9170FW_UNUSABLE) ||
 	    !SUPP(CARL9170FW_HANDLE_BACK_REQ)) {
 		dev_err(&ar->udev->dev, "firmware does support "
 			"mandatory features.\n");
 		return -ECANCELED;
 	}

 	if (ilog2(le32_to_cpu(otus_desc->feature_set)) >=
 		__CARL9170FW_FEATURE_NUM) {
 		dev_warn(&ar->udev->dev, "driver does not support all "
 			 "firmware features.\n");
 	}

 	if (!SUPP(CARL9170FW_COMMAND_CAM)) {
 		dev_info(&ar->udev->dev, "crypto offloading is disabled "
 			 "by firmware.\n");
 		ar->fw.disable_offload_fw = true;
 	}

 	if (SUPP(CARL9170FW_PSM) && SUPP(CARL9170FW_FIXED_5GHZ_PSM))
 		ieee80211_hw_set(ar->hw, SUPPORTS_PS);

 	if (!SUPP(CARL9170FW_USB_INIT_FIRMWARE)) {
 		dev_err(&ar->udev->dev, "firmware does not provide "
 			"mandatory interfaces.\n");
 		return -EINVAL;
 	}

 	if (SUPP(CARL9170FW_MINIBOOT))
 		ar->fw.offset = le16_to_cpu(otus_desc->miniboot_size);
 	else
 		ar->fw.offset = 0;

 	if (SUPP(CARL9170FW_USB_DOWN_STREAM)) {
 		ar->hw->extra_tx_headroom += sizeof(struct ar9170_stream);
 		ar->fw.tx_stream = true;
 	}

 	if (SUPP(CARL9170FW_USB_UP_STREAM))
 		ar->fw.rx_stream = true;

 	if (SUPP(CARL9170FW_RX_FILTER)) {
 		ar->fw.rx_filter = true;
 		ar->rx_filter_caps = FIF_FCSFAIL | FIF_PLCPFAIL |
 			FIF_CONTROL | FIF_PSPOLL | FIF_OTHER_BSS;
 	}

 	if (SUPP(CARL9170FW_HW_COUNTERS))
 		ar->fw.hw_counters = true;

 	if (SUPP(CARL9170FW_WOL))
 		device_set_wakeup_enable(&ar->udev->dev, true);

 	if (SUPP(CARL9170FW_RX_BA_FILTER))
 		ar->fw.ba_filter = true;

 	if_comb_types = BIT(NL80211_IFTYPE_STATION) |
 			BIT(NL80211_IFTYPE_P2P_CLIENT);

 	ar->fw.vif_num = otus_desc->vif_num;
 	ar->fw.cmd_bufs = otus_desc->cmd_bufs;
 	ar->fw.address = le32_to_cpu(otus_desc->fw_address);
 	ar->fw.rx_size = le16_to_cpu(otus_desc->rx_max_frame_len);
 	ar->fw.mem_blocks = min_t(unsigned int, otus_desc->tx_descs, 0xfe);
 	atomic_set(&ar->mem_free_blocks, ar->fw.mem_blocks);
 	ar->fw.mem_block_size = le16_to_cpu(otus_desc->tx_frag_len);

 	if (ar->fw.vif_num >= AR9170_MAX_VIRTUAL_MAC || !ar->fw.vif_num ||
 	    ar->fw.mem_blocks < 16 || !ar->fw.cmd_bufs ||
 	    ar->fw.mem_block_size < 64 || ar->fw.mem_block_size > 512 ||
 	    ar->fw.rx_size > 32768 || ar->fw.rx_size < 4096 ||
 	    !valid_cpu_addr(ar->fw.address)) {
 		dev_err(&ar->udev->dev, "firmware shows obvious signs of "
 			"malicious tampering.\n");
 		return -EINVAL;
 	}

 	ar->fw.beacon_addr = le32_to_cpu(otus_desc->bcn_addr);
 	ar->fw.beacon_max_len = le16_to_cpu(otus_desc->bcn_len);

 	if (valid_dma_addr(ar->fw.beacon_addr) && ar->fw.beacon_max_len >=
 	    AR9170_MAC_BCN_LENGTH_MAX) {
 		ar->hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_ADHOC);

 		if (SUPP(CARL9170FW_WLANTX_CAB)) {
 			if_comb_types |=
 				BIT(NL80211_IFTYPE_AP) |
 				BIT(NL80211_IFTYPE_P2P_GO);

 #ifdef CONFIG_MAC80211_MESH
 			if_comb_types |=
 				BIT(NL80211_IFTYPE_MESH_POINT);
 #endif /* CONFIG_MAC80211_MESH */
 		}
 	}

 	carl9170_fw_set_if_combinations(ar, if_comb_types);

 	ar->hw->wiphy->interface_modes |= if_comb_types;

 	ar->hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;

 	/* As IBSS Encryption is software-based, IBSS RSN is supported. */
 	ar->hw->wiphy->flags |= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL |
 		 WIPHY_FLAG_IBSS_RSN | WIPHY_FLAG_SUPPORTS_TDLS;

 #undef SUPPORTED
 	return carl9170_fw_tx_sequence(ar);
 }

 static struct carl9170fw_desc_head *
 carl9170_find_fw_desc(struct ar9170 *ar, const __u8 *fw_data, const size_t len)

 {
 	int scan = 0, found = 0;

 	if (!carl9170fw_size_check(len)) {
 		dev_err(&ar->udev->dev, "firmware size is out of bound.\n");
 		return NULL;
 	}

 	while (scan < len - sizeof(struct carl9170fw_desc_head)) {
 		if (fw_data[scan++] == otus_magic[found])
 			found++;
 		else
 			found = 0;

 		if (scan >= len)
 			break;

 		if (found == sizeof(otus_magic))
 			break;
 	}

 	if (found != sizeof(otus_magic))
 		return NULL;

 	return (void *)&fw_data[scan - found];
 }

 int carl9170_parse_firmware(struct ar9170 *ar)
 {
 	const struct carl9170fw_desc_head *fw_desc = NULL;
 	const struct firmware *fw = ar->fw.fw;
 	unsigned long header_offset = 0;
 	int err;

 	if (WARN_ON(!fw))
 		return -EINVAL;

 	fw_desc = carl9170_find_fw_desc(ar, fw->data, fw->size);

 	if (!fw_desc) {
 		dev_err(&ar->udev->dev, "unsupported firmware.\n");
 		return -ENODATA;
 	}

 	header_offset = (unsigned long)fw_desc - (unsigned long)fw->data;

 	err = carl9170_fw_verify_descs(ar, fw_desc, fw->size - header_offset);
 	if (err) {
 		dev_err(&ar->udev->dev, "damaged firmware (%d).\n", err);
 		return err;
 	}

 	ar->fw.desc = fw_desc;

 	carl9170_fw_info(ar);

 	err = carl9170_fw(ar, fw->data, fw->size);
 	if (err) {
 		dev_err(&ar->udev->dev, "failed to parse firmware (%d).\n",
 			err);
 		return err;
 	}

 	return 0;
 }
	/*
	* Atheros CARL9170 driver
	*
	* firmware parser
	*
	* Copyright 2009, 2010, Christian Lamparter <chunkeey@googlemail.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; see the file COPYING. If not, see
	* http://www.gnu.org/licenses/.
	*/

	#include <linux/kernel.h>
	#include <linux/firmware.h>
	#include <linux/crc32.h>
	#include <linux/module.h>
	#include "carl9170.h"
	#include "fwcmd.h"
	#include "version.h"

	static const u8 otus_magic[4] = { OTUS_MAGIC };

	static const void carl9170_fw_find_desc(struct ar9170 ar, const u8 descid[4],
	const unsigned int len, const u8 compatible_revision)
	{
	const struct carl9170fw_desc_head *iter;

	carl9170fw_for_each_hdr(iter, ar->fw.desc) {
	if (carl9170fw_desc_cmp(iter, descid, len,
	compatible_revision))
	return (void *)iter;
	}

	/* needed to find the LAST desc */
	if (carl9170fw_desc_cmp(iter, descid, len,
	compatible_revision))
	return (void *)iter;

	return NULL;
	}

	static int carl9170_fw_verify_descs(struct ar9170 *ar,
	const struct carl9170fw_desc_head *head, unsigned int max_len)
	{
	const struct carl9170fw_desc_head *pos;
	unsigned long pos_addr, end_addr;
	unsigned int pos_length;

	if (max_len < sizeof(*pos))
	return -ENODATA;

	max_len = min_t(unsigned int, CARL9170FW_DESC_MAX_LENGTH, max_len);

	pos = head;
	pos_addr = (unsigned long) pos;
	end_addr = pos_addr + max_len;

	while (pos_addr < end_addr) {
	if (pos_addr + sizeof(*head) > end_addr)
	return -E2BIG;

	pos_length = le16_to_cpu(pos->length);

	if (pos_length < sizeof(*head))
	return -EBADMSG;

	if (pos_length > max_len)
	return -EOVERFLOW;

	if (pos_addr + pos_length > end_addr)
	return -EMSGSIZE;

	if (carl9170fw_desc_cmp(pos, LAST_MAGIC,
	CARL9170FW_LAST_DESC_SIZE,
	CARL9170FW_LAST_DESC_CUR_VER))
	return 0;

	pos_addr += pos_length;
	pos = (void *)pos_addr;
	max_len -= pos_length;
	}
	return -EINVAL;
	}

	static void carl9170_fw_info(struct ar9170 *ar)
	{
	const struct carl9170fw_motd_desc *motd_desc;
	unsigned int str_ver_len;
	u32 fw_date;

	dev_info(&ar->udev->dev, "driver API: %s 2%03d-%02d-%02d [%d-%d]\n",
	CARL9170FW_VERSION_GIT, CARL9170FW_VERSION_YEAR,
	CARL9170FW_VERSION_MONTH, CARL9170FW_VERSION_DAY,
	CARL9170FW_API_MIN_VER, CARL9170FW_API_MAX_VER);

	motd_desc = carl9170_fw_find_desc(ar, MOTD_MAGIC,
	sizeof(*motd_desc), CARL9170FW_MOTD_DESC_CUR_VER);

	if (motd_desc) {
	str_ver_len = strnlen(motd_desc->release,
	CARL9170FW_MOTD_RELEASE_LEN);

	fw_date = le32_to_cpu(motd_desc->fw_year_month_day);

	dev_info(&ar->udev->dev, "firmware API: %.*s 2%03d-%02d-%02d\n",
	str_ver_len, motd_desc->release,
	CARL9170FW_GET_YEAR(fw_date),
	CARL9170FW_GET_MONTH(fw_date),
	CARL9170FW_GET_DAY(fw_date));

	strlcpy(ar->hw->wiphy->fw_version, motd_desc->release,
	sizeof(ar->hw->wiphy->fw_version));
	}
	}

	static bool valid_dma_addr(const u32 address)
	{
	if (address >= AR9170_SRAM_OFFSET &&
	address < (AR9170_SRAM_OFFSET + AR9170_SRAM_SIZE))
	return true;

	return false;
	}

	static bool valid_cpu_addr(const u32 address)
	{
	if (valid_dma_addr(address) \|\| (address >= AR9170_PRAM_OFFSET &&
	address < (AR9170_PRAM_OFFSET + AR9170_PRAM_SIZE)))
	return true;

	return false;
	}

	static int carl9170_fw_checksum(struct ar9170 ar, const __u8 data,
	size_t len)
	{
	const struct carl9170fw_otus_desc *otus_desc;
	const struct carl9170fw_last_desc *last_desc;
	const struct carl9170fw_chk_desc *chk_desc;
	unsigned long fin, diff;
	unsigned int dsc_len;
	u32 crc32;

	last_desc = carl9170_fw_find_desc(ar, LAST_MAGIC,
	sizeof(*last_desc), CARL9170FW_LAST_DESC_CUR_VER);
	if (!last_desc)
	return -EINVAL;

	otus_desc = carl9170_fw_find_desc(ar, OTUS_MAGIC,
	sizeof(*otus_desc), CARL9170FW_OTUS_DESC_CUR_VER);
	if (!otus_desc) {
	dev_err(&ar->udev->dev, "failed to find compatible firmware "
	"descriptor.\n");
	return -ENODATA;
	}

	chk_desc = carl9170_fw_find_desc(ar, CHK_MAGIC,
	sizeof(*chk_desc), CARL9170FW_CHK_DESC_CUR_VER);

	if (!chk_desc) {
	dev_warn(&ar->udev->dev, "Unprotected firmware image.\n");
	return 0;
	}

	dsc_len = min_t(unsigned int, len,
	(unsigned long)chk_desc - (unsigned long)otus_desc);

	fin = (unsigned long) last_desc + sizeof(*last_desc);
	diff = fin - (unsigned long) otus_desc;

	if (diff < len)
	len -= diff;

	if (len < 256)
	return -EIO;

	crc32 = crc32_le(~0, data, len);
	if (cpu_to_le32(crc32) != chk_desc->fw_crc32) {
	dev_err(&ar->udev->dev, "fw checksum test failed.\n");
	return -ENOEXEC;
	}

	crc32 = crc32_le(crc32, (void *)otus_desc, dsc_len);
	if (cpu_to_le32(crc32) != chk_desc->hdr_crc32) {
	dev_err(&ar->udev->dev, "descriptor check failed.\n");
	return -EINVAL;
	}
	return 0;
	}

	static int carl9170_fw_tx_sequence(struct ar9170 *ar)
	{
	const struct carl9170fw_txsq_desc *txsq_desc;

	txsq_desc = carl9170_fw_find_desc(ar, TXSQ_MAGIC, sizeof(*txsq_desc),
	CARL9170FW_TXSQ_DESC_CUR_VER);
	if (txsq_desc) {
	ar->fw.tx_seq_table = le32_to_cpu(txsq_desc->seq_table_addr);
	if (!valid_cpu_addr(ar->fw.tx_seq_table))
	return -EINVAL;
	} else {
	ar->fw.tx_seq_table = 0;
	}

	return 0;
	}

	static void carl9170_fw_set_if_combinations(struct ar9170 *ar,
	u16 if_comb_types)
	{
	if (ar->fw.vif_num < 2)
	return;

	ar->if_comb_limits[0].max = ar->fw.vif_num;
	ar->if_comb_limits[0].types = if_comb_types;

	ar->if_combs[0].num_different_channels = 1;
	ar->if_combs[0].max_interfaces = ar->fw.vif_num;
	ar->if_combs[0].limits = ar->if_comb_limits;
	ar->if_combs[0].n_limits = ARRAY_SIZE(ar->if_comb_limits);

	ar->hw->wiphy->iface_combinations = ar->if_combs;
	ar->hw->wiphy->n_iface_combinations = ARRAY_SIZE(ar->if_combs);
	}

	static int carl9170_fw(struct ar9170 ar, const __u8 data, size_t len)
	{
	const struct carl9170fw_otus_desc *otus_desc;
	int err;
	u16 if_comb_types;

	err = carl9170_fw_checksum(ar, data, len);
	if (err)
	return err;

	otus_desc = carl9170_fw_find_desc(ar, OTUS_MAGIC,
	sizeof(*otus_desc), CARL9170FW_OTUS_DESC_CUR_VER);
	if (!otus_desc) {
	return -ENODATA;
	}

	#define SUPP(feat) \
	(carl9170fw_supports(otus_desc->feature_set, feat))

	if (!SUPP(CARL9170FW_DUMMY_FEATURE)) {
	dev_err(&ar->udev->dev, "invalid firmware descriptor "
	"format detected.\n");
	return -EINVAL;
	}

	ar->fw.api_version = otus_desc->api_ver;

	if (ar->fw.api_version < CARL9170FW_API_MIN_VER \|\|
	ar->fw.api_version > CARL9170FW_API_MAX_VER) {
	dev_err(&ar->udev->dev, "unsupported firmware api version.\n");
	return -EINVAL;
	}

	if (!SUPP(CARL9170FW_COMMAND_PHY) \|\| SUPP(CARL9170FW_UNUSABLE) \|\|
	!SUPP(CARL9170FW_HANDLE_BACK_REQ)) {
	dev_err(&ar->udev->dev, "firmware does support "
	"mandatory features.\n");
	return -ECANCELED;
	}

	if (ilog2(le32_to_cpu(otus_desc->feature_set)) >=
	__CARL9170FW_FEATURE_NUM) {
	dev_warn(&ar->udev->dev, "driver does not support all "
	"firmware features.\n");
	}

	if (!SUPP(CARL9170FW_COMMAND_CAM)) {
	dev_info(&ar->udev->dev, "crypto offloading is disabled "
	"by firmware.\n");
	ar->fw.disable_offload_fw = true;
	}

	if (SUPP(CARL9170FW_PSM) && SUPP(CARL9170FW_FIXED_5GHZ_PSM))
	ieee80211_hw_set(ar->hw, SUPPORTS_PS);

	if (!SUPP(CARL9170FW_USB_INIT_FIRMWARE)) {
	dev_err(&ar->udev->dev, "firmware does not provide "
	"mandatory interfaces.\n");
	return -EINVAL;
	}

	if (SUPP(CARL9170FW_MINIBOOT))
	ar->fw.offset = le16_to_cpu(otus_desc->miniboot_size);
	else
	ar->fw.offset = 0;

	if (SUPP(CARL9170FW_USB_DOWN_STREAM)) {
	ar->hw->extra_tx_headroom += sizeof(struct ar9170_stream);
	ar->fw.tx_stream = true;
	}

	if (SUPP(CARL9170FW_USB_UP_STREAM))
	ar->fw.rx_stream = true;

	if (SUPP(CARL9170FW_RX_FILTER)) {
	ar->fw.rx_filter = true;
	ar->rx_filter_caps = FIF_FCSFAIL \| FIF_PLCPFAIL \|
	FIF_CONTROL \| FIF_PSPOLL \| FIF_OTHER_BSS;
	}

	if (SUPP(CARL9170FW_HW_COUNTERS))
	ar->fw.hw_counters = true;

	if (SUPP(CARL9170FW_WOL))
	device_set_wakeup_enable(&ar->udev->dev, true);

	if (SUPP(CARL9170FW_RX_BA_FILTER))
	ar->fw.ba_filter = true;

	if_comb_types = BIT(NL80211_IFTYPE_STATION) \|
	BIT(NL80211_IFTYPE_P2P_CLIENT);

	ar->fw.vif_num = otus_desc->vif_num;
	ar->fw.cmd_bufs = otus_desc->cmd_bufs;
	ar->fw.address = le32_to_cpu(otus_desc->fw_address);
	ar->fw.rx_size = le16_to_cpu(otus_desc->rx_max_frame_len);
	ar->fw.mem_blocks = min_t(unsigned int, otus_desc->tx_descs, 0xfe);
	atomic_set(&ar->mem_free_blocks, ar->fw.mem_blocks);
	ar->fw.mem_block_size = le16_to_cpu(otus_desc->tx_frag_len);

	if (ar->fw.vif_num >= AR9170_MAX_VIRTUAL_MAC \|\| !ar->fw.vif_num \|\|
	ar->fw.mem_blocks < 16 \|\| !ar->fw.cmd_bufs \|\|
	ar->fw.mem_block_size < 64 \|\| ar->fw.mem_block_size > 512 \|\|
	ar->fw.rx_size > 32768 \|\| ar->fw.rx_size < 4096 \|\|
	!valid_cpu_addr(ar->fw.address)) {
	dev_err(&ar->udev->dev, "firmware shows obvious signs of "
	"malicious tampering.\n");
	return -EINVAL;
	}

	ar->fw.beacon_addr = le32_to_cpu(otus_desc->bcn_addr);
	ar->fw.beacon_max_len = le16_to_cpu(otus_desc->bcn_len);

	if (valid_dma_addr(ar->fw.beacon_addr) && ar->fw.beacon_max_len >=
	AR9170_MAC_BCN_LENGTH_MAX) {
	ar->hw->wiphy->interface_modes \|= BIT(NL80211_IFTYPE_ADHOC);

	if (SUPP(CARL9170FW_WLANTX_CAB)) {
	if_comb_types \|=
	BIT(NL80211_IFTYPE_AP) \|
	BIT(NL80211_IFTYPE_P2P_GO);

	#ifdef CONFIG_MAC80211_MESH
	if_comb_types \|=
	BIT(NL80211_IFTYPE_MESH_POINT);
	#endif /* CONFIG_MAC80211_MESH */
	}
	}

	carl9170_fw_set_if_combinations(ar, if_comb_types);

	ar->hw->wiphy->interface_modes \|= if_comb_types;

	ar->hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;

	/* As IBSS Encryption is software-based, IBSS RSN is supported. */
	ar->hw->wiphy->flags \|= WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL \|
	WIPHY_FLAG_IBSS_RSN \| WIPHY_FLAG_SUPPORTS_TDLS;

	#undef SUPPORTED
	return carl9170_fw_tx_sequence(ar);
	}

	static struct carl9170fw_desc_head *
	carl9170_find_fw_desc(struct ar9170 ar, const __u8 fw_data, const size_t len)

	{
	int scan = 0, found = 0;

	if (!carl9170fw_size_check(len)) {
	dev_err(&ar->udev->dev, "firmware size is out of bound.\n");
	return NULL;
	}

	while (scan < len - sizeof(struct carl9170fw_desc_head)) {
	if (fw_data[scan++] == otus_magic[found])
	found++;
	else
	found = 0;

	if (scan >= len)
	break;

	if (found == sizeof(otus_magic))
	break;
	}

	if (found != sizeof(otus_magic))
	return NULL;

	return (void *)&fw_data[scan - found];
	}

	int carl9170_parse_firmware(struct ar9170 *ar)
	{
	const struct carl9170fw_desc_head *fw_desc = NULL;
	const struct firmware *fw = ar->fw.fw;
	unsigned long header_offset = 0;
	int err;

	if (WARN_ON(!fw))
	return -EINVAL;

	fw_desc = carl9170_find_fw_desc(ar, fw->data, fw->size);

	if (!fw_desc) {
	dev_err(&ar->udev->dev, "unsupported firmware.\n");
	return -ENODATA;
	}

	header_offset = (unsigned long)fw_desc - (unsigned long)fw->data;

	err = carl9170_fw_verify_descs(ar, fw_desc, fw->size - header_offset);
	if (err) {
	dev_err(&ar->udev->dev, "damaged firmware (%d).\n", err);
	return err;
	}

	ar->fw.desc = fw_desc;

	carl9170_fw_info(ar);

	err = carl9170_fw(ar, fw->data, fw->size);
	if (err) {
	dev_err(&ar->udev->dev, "failed to parse firmware (%d).\n",
	err);
	return err;
	}

	return 0;
	}